A traditional pen barrel generally has a circular shape. In order to improve the aesthetic appearance of the pen, a pattern is often heat transferred onto the surface of the pen barrel. A conventional heat transferring device generally includes a pneumatic mechanism, a roller mechanism for heat transferring on the pen barrel, and a heating mechanism for heating the roller mechanism. When heat transferring on a pen barrel, the pneumatic mechanism pushes the roller mechanism downwards to contact the pen barrel and rotates the pen barrel in order to heat transfer a pattern from a pattern paper onto the outer surface of the pen barrel.
When a pen barrel has a circular shape, the roller mechanism stays in contact with the pen barrel during heat transferring, so a uniform force is applied along the length of the pen barrel. Since each face of the pen barrel receives a uniform force, the pen barrel rolls at an even speed.
As pen manufacturing technology improves, the aesthetic appearance of the pen also improves, and various shapes of pen barrels have appeared, such as triangle, quadrangle, or other irregular shapes. When heat transferring on pen barrels of triangle, quadrangle, or other irregular shapes, the roller mechanism cannot keep in contact with each face of the pen barrel as the conventional roller wheel is made of a very hard material. The result is that the roller mechanism cannot apply a uniform force on different faces of the pen barrel. Because each face of the pen barrel receives a nonuniform force, the roller mechanism cannot smoothly roll the pen barrel. Therefore, it is difficult to complete heat transferring and printing.